Backlight Current Control Circuit for LCD Flicker Reduction
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Solution Overview
Problem
Existing backlight devices for LCD panels face challenges in maintaining light emission for one frame to prevent flicker and in uniformly controlling luminance across the entire luminance change area.
Innovation Solution
A backlight device with a current control integrated circuit that uses a combination of linear control and pulse width control to manage the driving current for light emitting blocks, ensuring consistent light emission and reduced flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dimming control is used for light emitting blocks, then the device complexity is reduced, but flicker occurs because light emission cannot be maintained for one frame
Solution Approach 1:
The backlight board is divided into multiple light emitting blocks that can be independently controlled. Each block is assigned to specific control units with dedicated driving current control, allowing selective dimming control for different regions while maintaining overall stability and preventing flicker.
Solution Approach 2:
The system performs preliminary sampling of column signals during the horizontal period before actual light emission. By sampling the first and second column signals in advance and preparing driving currents beforehand, the system ensures continuous light emission without flicker while maintaining simplified control architecture.
2Manufacturing precision
If simple current control is used for light emitting blocks, then the device complexity is reduced, but luminance cannot be uniformly controlled across the entire luminance change area
Solution Approach 1:
Different control strategies are applied to different regions of the backlight board. The system uses first column signals and second column signals with different weightings depending on the luminance requirements of specific areas, enabling precise local luminance control while maintaining overall uniformity across the display.
Solution Approach 2:
The system dynamically adjusts driving currents based on sampled column signal levels. By continuously sampling and adapting the driving current amounts according to real-time luminance requirements, the system achieves uniform luminance control across varying luminance change areas without requiring overly complex static control circuits.
3Manufacturing precision
If frame-unit backlight data is generated for the entire frame, then luminance uniformity is improved, but the response speed decreases due to processing the entire frame at once
Solution Approach 1:
Frame-unit backlight data is segmented into horizontal periods with column signals processed independently. By dividing the frame into manageable horizontal periods and processing column signals for each period separately, the system maintains luminance uniformity across the entire frame while significantly improving control response speed through parallel processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively maintains light emission for one frame or more, reduces or eliminates flicker, and uniformly controls luminance across the entire luminance change area, enhancing the display quality of LCD panels.
Implementation Method 1
light emitting blocks using LEDs as light sources, and the light emitting blocks may emit light to provide a backlight
Data Source
AI summary
Disclosed are a backlight device for a display that provides a backlight for displaying an image and a current control integrated circuit thereof. According to the backlight device and the current control integrated circuit thereof, a driving current can be controlled so as to allow light emitting blocks to maintain light emission for one frame or more, and the luminance of a backlight can be uniformly and precisely controlled in an entire luminance change area.